pcname is not setup to establish a connection on port "File and Print Sharing (SMB)" with this computer

If you've run into this charming message trying to get some file sharing up and running - try flipping this registry key:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanManWorkstation\Parameters

EnableSecuritySignature 

Change it to 0. This toggles SMB signing. Tested on Vista. Dont forget the other usaul suspects - firewalls, antivirus, ect.